Skip to main content
U.S. flag

An official website of the United States government

Parkinsonia L.

Informally Refereed

Abstract

There are three noteworthy species of Parkinsonia grown in the United States. Palo verde is a thorny, green-barked shrub/small tree which can reach a height of 11 m. The name refers to the very noticeable green color of the smooth trunk of this drought-resistant tree of the hot southern deserts. The open-crowned trees have alternate, bipinnate leaves on slightly zig-zag green twigs. The species is widely distributed in tropical America and widely planted in the southwestern United States and the old world tropics. Blue palo verde and yellow palo verde are two closely-related species, commonly found on the edges of washes and more occasionally in washes. Both species drop their leaves when drought-stressed and only the green, thorny branches remain. The three species serve as shelter for animals and rodents, and the leaves and pods as browse for livestock, rodents, rabbits, other mammals, and many species of birds. In the past, the legumes were a fairly important food for natives of the Sonoran Desert. Palo verdes have fragrant 5-petaled, showy, yellow flowers that form in loose racemes 5 to 20 cm long. In the past, these trees have been referred to as “lluvia de oro” or “fountain of gold” by Spanish Americans because of their incredible flower show after a generous rainy season. The fruits are 5 to 10 cm long, pointed legumes that contain 1 to 8 oblong, glossy, yellow-brown seeds. The fruits are ripe when the legume turns yellow-brown and the seeds rattle. Seed collection should be timely since harvesting by animals and birds quickly reduces seed availability. Pods dehisce upon drying and small quantities of seeds can be hand-cleaned. A disc mill, meat grinder, or hammer mill can be used to clean larger quantities.

Keywords

Parkinsonia, seed research, palo verde

Citation

Connor, Kristina F.; Rodgers, Jane E.; Miller, Carol. 2008. Parkinsonia L. In: Bonner, Franklin T.; Karrfalt, Robert P., eds. The Woody Plant Seed Manual. Agric. Handbook No. 727. Washington, DC. U.S. Department of Agriculture, Forest Service. 766-768.
https://www.fs.usda.gov/research/treesearch/42349